Commitments and contingencies.

No definition available.

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- Definition

Expected lease commencement period.

+ References

No definition available.

+ Details

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- Definition

Lease commencement date.

+ References

No definition available.

+ Details

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- Definition

Lease commencement period.

+ References

No definition available.

+ Details

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- Definition

Lessee, operating lease, lease not yet commenced, tenant improvement allowance.

+ References

No definition available.

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- Definition

Lessee, operating lease, liability, tenant improvement allowance.

+ References

No definition available.

+ Details

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- Definition

Lessee, Operating Lease, Number Of Contracts

+ References

No definition available.

+ Details

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- Definition

Area of land subject to a ground lease.

+ References

No definition available.

+ Details

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- Definition

Date which lease or group of leases is set to expire, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates (true false) whether lessee has option to extend operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

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Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of terms and conditions of option to extend lessee's operating lease. Includes, but is not limited to, information about option recognized as part of right-of-use asset and lease liability.

+ References

+ Details

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- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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-SubTopic 20
-Section 50
-Paragraph 3
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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Weighted average discount rate for operating lease calculated at point in time.

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

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Commitments and Contingencies - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) ft²	Mar. 31, 2019	Sep. 30, 2019 USD ($) ft² contract	Jun. 30, 2019 ft²	Jan. 31, 2019 ft²
Commitments And Contingencies [Line Items]
Operating lease costs \| $	$ 2.6		$ 5.3
Lease option to extend			true
Variable lease expense \| $	$ 0.6		$ 1.2
Cash paid for operating lease liabilities included net cash used in operating activities \| $			$ 2.0
Operating lease, weighted-average remaining lease term	9 years 1 month 6 days		9 years 1 month 6 days
Operating lease, weighted-average discount rate	6.90%		6.90%
Richmond Lease \| Office and Laboratory
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)	37,900		37,900
Richmond Lease \| Operating Lease One \| Research and Office Space
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)	7,700		7,700
Lease expiration date			Aug. 31, 2019
Valbonne Lease
Commitments And Contingencies [Line Items]
Additional property available under lease \| contract			2
Valbonne Lease \| Operating Lease One \| Research and Office Space
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)	14,036		14,036
Valbonne Lease \| Operating Lease Two \| Office Space
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)	6,800		6,800
Lease commencement date		Apr. 01, 2019
Richmond and Valbonne Leases
Commitments And Contingencies [Line Items]
Lease option to extend			Certain of these leases also include renewal options at the election of the Company to renew or extend the lease for an additional five to ten years.
Richmond and Valbonne Leases \| Minimum
Commitments And Contingencies [Line Items]
Lease agreement, extendable lease term	5 years		5 years
Richmond and Valbonne Leases \| Maximum
Commitments And Contingencies [Line Items]
Lease agreement, extendable lease term	10 years		10 years
Brisbane Lease
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)				52,620
Expected lease commencement period			2019-06
Tenant improvement allowance \| $	$ 6.8		$ 6.8
Lease not yet commenced, tenant improvement allowance \| $	$ 10.2		$ 10.2
Brisbane Lease \| Office and Laboratory
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)	87,700		87,700
Brisbane Lease \| Office Space
Commitments And Contingencies [Line Items]
Area of space leased (in sqft)					35,080
Lease commencement period			2019-01